METHOD OF PRODUCING IMAZAMOX HERBICIDE Russian patent published in 2019 - IPC A01N31/06 A01N43/40 A01N43/50 C07D213/55 C07D233/20 C07D233/22 A01P13/02 

FIELD: chemistry.

SUBSTANCE: invention relates to production of pesticides, in particular to the technology of producing an impervious imazamox herbicide, having a chemical structure (±)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-(methoxymethyl)-3-pyridinecarboxylic acid. Method of producing (±)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-(methoxymethyl)-3-pyridinecarboxylic acid (imazamox) includes synthesis of imazamox salt from 5-methoxymethyl-2,3-pyridine dicarboxylic acid dimethyl ester and (±)-2-amino-2,3-dimethylbutyramide in the presence of sodium or potassium tert-butoxide in toluene or xylene while heating, dissolution of the obtained salt in water and separation of toluene or xylene, subsequent conversion of the obtained imazamox salt to the end product under action of hydrochloric or sulfuric acid and extraction of the end product. Moisture is previously removed from solution of 5-methoxymethyl-2,3-pyridine dicarboxylic acid dimethyl ether and (±)-2-amino-2,3-dimethylbutyramide in toluene or xylene by azeotropic distillation, and the process of producing the imazamox salt is carried out in an atmosphere of an inert gas. Obtained solution of imazamox salt is purified at stirring with 6–12 wt% of activated carbon in terms of initial dimethyl ester of 5-methoxymethyl-2,3-pyridine dicarboxylic acid for 1–2 hours and spent activated carbon is filtered. Obtained imazamox salt solution is acidified to acidic pH values, the precipitated residue of the end product is separated by filtration, washing with water and drying.

EFFECT: disclosed method of producing (±)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-(methoxymethyl)-3-pyridinecarboxylic acid (imazamox) provides simplified process of imazamox production, which is expressed in the fact that the use of an anhydrous solvent is excluded, the extraction stages are excluded with high-corrosion solvents, the organic extract is dried and purified, the organochloride compounds evaporated, and the end product yield is equal to 83,6 %.

1 cl